Interphase transformer configuration

ABSTRACT

A rectifier system which includes a plurality of diodes in the secondary circuit thereof to provide rectification for the energy flowing from a main transformer connected to the source of alternating current power, the configuration including a plurality of parallel diodes in each phase to increase the current-carrying capabilities and an interphase transformer interconnected with each set of phase diodes, the interphase transformers being physically stacked in the rectifier assembly to facilitate the increasing of the number of paralleled diodes and thus the number of paralleled interphase transformers. The interphase transformers are stacked within two channels, the channels being bolted together to squeeze the cores of the interphase transformers. A common conductor is electrically connected, as by welding, to a center portion of the interphase transformer turns, the common conductor providing a common output conductor for all of the center taps of the interphase winding.

United States Patent [72] Inventor Eugene W. Rabut Shelby Township,Macomb County, Mich. [2 1] Appl. No. 88,343

[ 22] Filed [45] Patented [73] Assignee Nov. 10, 1970 NOV. 30, 1971 TheUdylite Corporation Warren, Mich.

[54] INTERPHASE TRANSFORMER CONFIGURATION 3,513,377 5/l970 Koltuniaketal.

Attorney-Harness, Dickey & Pierce ABSTRACT: A rectifier system whichincludes a plurality of diodes in the secondary circuit thereof toprovide rectification for the energy flowing from a main transformerconnected to the source of alternating current power, the configurationincluding a plurality of parallel diodes in each phase to increase thecurrent-carrying capabilities and an interphase transformerinterconnected with each set of phase diodes, the interphasetransformers being physically stacked in the rectifier assembly tofacilitate the increasing of the number of paralleled diodes and thusthe number of paralleled interphase transformers. The interphasetransformers are stacked within two channels, the channels being boltedtogether to squeeze the cores of the interphase transformers. A commonconductor is electrically connected, as by welding, to a center portionof the interphase transformer turns, the common conductor providing acommon output conductor for all of the center taps of the interphasewinding.

PATENTED nuvso I97! SHEET 1 OF 3 INVENTOR.

1/1 /71 ,QZ/(ff PAIENIEnumom 3.624.488

SHEET 3 OF 3 BY f /f iyf INTERPHASE TRANSFORMER CONFIGURATION Thepurpose of the foregoing abstract is to enable the US. Pat. Office andthe public generally. and especially the scientists, engineers orpractitioners in the art who are not familiar with patent or legal termsor phraseology, to determine quickly from a cursory inspection thenature and essence of the technical disclosure of the application. Theabstract is neither intended to define the invention of the application,which is measured by claims, nor is it intended to be limiting as to thescope of the invention in any way.

BACKGROUND ANDSUMMARY OF THE DISCLOSURE This invention relates generallyto a configuration for a rectifier assembly and, more particularly, to asystem for supporting the interphase transformers utilized in arectifier system and for providing interconnections between therectifying diodes and the interphase transformers, the system alsoincluding a provision for expanding the interphase transformer andrectifier diodes into a parallel combination.

As is well known, rectifier systems for use, particularly in, interalia, electrochemical processes such as electrochemical plating andanodizing, require a large range of current ratings to accommodate therequirements of relatively small units, such as are used in preciousmetal plating, to extremely large units of the to 20,000 ampere range.Particularly, in the larger units, it has been found necessary toprovide diode paralleling in the output circuit to permit the increasedcurrent rating without the necessity of utilizing extremely highcurrent-rated rectifier devices. Such a parallel diode system isillustrated in U.S. Pat. No. 3,513,377 issued May 19, 1970, forIndividual interphase Transformers.

In referring to that patent, it will be noted that a necessity hasarisen, for circuit balance and other considerations, to provideinterphase transformers at the output terminal of the paralleled diodes.The interphase transformer typically consists of magnetic core and arelatively large conductor having a few turns, for example, one or twoturns.

In prior systems which provided parallel diodes and interconnectedinterphase transformers, a problem has arisen in supporting the coresfor the paralleled interphase transformers and in bussing the windingassociated with the transformer. Further, with changes in voltage withinthe rectifier system, it is necessary to provide cores and coils ofdifferent electrical characteristics to accommodate the difference involtages from one family of rectifier ratings to another. Thus, aninventory of various sizes of conductors and cores is necessary.

Further, in systems utilized in the past, it was the practice to boltthe various elements together both for support of the various elementsand to provide electrical connections between the center taps of theparalleled interphase transformers and the output diodes and for thetransformer interconnections. This bolting arrangement creatednonuniform resistance characteristics atthe connection, was morecomplicated to assemble and required a great deal of quality control toinsure uniform electrical characteristics from one rectifier system tothe next.

With the system of the present invention, a mounting and connectionassembly has been evolved which eliminates or drastically reduces theaforementioned problems. In this system, the output connections for themain transformers are bussed by means of a standard bus bar and theoutput of each transformer is connected to a common support for all ofthe paralleled diodes for the particular phase involved. These latterbus bars or latter common supports are fluid cooled and provide anextremely simple and inexpensive mounting for the plurality ofparalleled diode elements.

The paralleled interphase transformers are mounted in the central areadefined by the six, in the case of a three-phase input supply, verticaldiodes support elements. in the illustrated embodiment, the common sidesof each of the input secondary windings are interconnected to threevertical common diode support assemblies and the opposite sides areinterconnected with three other vertical diodes support assemblies, thefirst support assemblies being supported in a common plane and thesecond support assemblies lying in a second common plane, the two planesbeing spaced and parallel, one from the other.

The interphase transformer cores are mounted within the above-definedspace and are supported relative to the vertical common supports bymeans of a pair of channels which are bolted together and squeezinglysupport the interphase transformer cores in vertical alignment. Therequired number of transformer core elements are stacked vertically andthe conductors within the cores are mounted in a horizontal plane, theends terminating in the space between the vertical common diode supportelements and relatively proximate thereto.

A common diode connection for one side of all three phases, in the caseof the three-phase system, is welded to the interphase transformerwinding conductor and the diode elements are interconnected between thecommon support element on which they are mounted and the commonconnection element is welded to the respective interphase transformerwinding.

With the system of the present invention, a relatively simplifiedbussing and support configuration has been provided which facilitatesthe assembly of the rectifier and further facilitates the inventory andthe expansion and contraction of the voltage and current rating for therectifier assembly. Further, the system of the present inventionprovides an improved method for more direct connection of the elementsof the rectifier and eliminates the use of bolts in connecting thevarious electrical circuit elements together. Also, standardizedconductors and core elements for the interphase transformer may beutilized and a standardized support element for all of the cores,irrespective of voltage or current ratings, are utilized in supportingthe interphase transformer cores.

The standardized conductors described above are provided with a centralcooling aperture through which a cooling medium is flowed, the coolingmedium thus flowing through the central portion of the core andextracting heat from the core, a system which has not been previouslyutilized in systems of this type.

Accordingly, it is one object of the present invention to provide animproved rectifier system.

It is another object of the present invention to provide an improvedsupport system for interphase transformers and rectifying elementsutilized in a rectifying system.

It is still another object of the present invention to provide animproved system for bussing the electrical components of a rectifiersystem.

it is still another object of the present invention to provide animproved configuration for paralleling rectifying elements andinterphase transformers.

It is still a further object of the present invention to provide animproved configuration for supporting paralleled rectifier diodes.

It is still a further object of the present invention to provide animproved system for interconnecting the center taps of interphasetransformers.

It is still a further object of the present invention to provide animproved system for supporting transformers cores in interphasetransformer systems.

It is a further object of the present invention to provide an improvedsystem for assembling a plurality of interphase transformer cores.

It is still another object of the present invention to provide animproved system for bussing the plurality of rectifying devices in amultiphase system to interphase transformer windings.

It is still another object of the present invention to provide animproved system for cooling interphase transformer cores.

It is still a further object of the present invention to provide animproved system for supporting and bussing the various elements of arectifier system including the bussing between the input maintransformer and rectifying diodes, and rectifying diodes and theinterphase transformers, and the interphase transformers and the outputbus.

It is still a further object of the present invention to provide animproved support assembly for the various bussing elements of arectifying system incorporating interphase transformers and rectifyingdevices.

It is still a further object of the present invention to provide animproved system for interconnecting the various electrical components ofthe system described above and substantially eliminating boltingelements for electrical connections.

It is still a further. object of the present invention to reduce thenumber of insulators utilized in a rectifying system.

It is a further object of the present invention to provide an improvedinterphase assembly which permits the standardization of interphasetransformer cores and conductors.

It is a further object of the present invention to provide an improvedclamping device for supporting a plurality of paralleled interphasetransformer cores.

It is still a further object of the present invention to provide animproved system for cooling both the conductors and cores of interphasetransformers.

It is a further object of the present invention to provide an improvedparalleled rectifying system incorporating interphase transformers whichis inexpensive to manufacture, reliable in use and which minimizes thedown time of the rectifier due to troubles or failures.

Further objects, features and advantages of this invention will becomeapparent from a consideration of the following description, the appendedclaims and the accompanying drawings in which:

FIG. I is a schematic diagram illustrating a typical multiphaserectifier system incorporating an interphase transformer system such asthat described in US Pat. No. 3,5 I 3,377;

FIG. 2 is a front view of a rectifier assembly in a cabinet with thedoor removed and incorporating certain features of the presentinvention;

FIG. 3 is a side view of the rectifier assembly of FIG. 2, the assemblyof FIG. 3 being illustrated with the exterior cabinet panels removed toillustrate the diode mounting assemblies and main input transformers;

FIG. 4 is a plan view, partially in cross section, of the interphasetransformer core and winding and further illustrating theinterconnection between the interphase transformer winding and therectifying diodes of the plural phase rectifying system;

FIG. 5 is an elevation view partially broken away of the interphasetransformer assembly of FIG. 2 with the front control circuit boards andsemicontrolled rectifier assemblies removed;

FIG. 6 is a side view of the interphase transformer assembly of FIG. 5;

FIG. 7 is a cross-sectional view of an interphase transformer coreassembly, taken along line 7-7 of FIG. 5; and

FIG. 8 is a composite schematic view of interphase transformerassemblies illustrating one and two interphase transformer cores toincrease the voltage which may be accommodated by the interphasetransformer.

Referring now to FIG. I there is illustrated a typical rectifying system10, illustrated from the secondary windings 18 of a multiphase secondarywindings 12, :14, 16 of a multiphase transformer to the output. Theprimary windings and the core of the main transformer are notillustrated, but it is understood that the typical primary windings andcore are utilized.

The secondary windings 12, l4, 16 are center tapped, at 20, 22, 24respectively, and the center-tap connections are connected together by abus bar 26 to provide a common centertap output connection at 28. Thecenter-tap connection 28, in the illustrated embodiment, forms thepositive terminal of the rectifying system.

Referring particularly to the first phase as generated across secondarywinding 12, the left end of the winding 12 is interconnected with acommon diode support heat sink 30 by means of a conductor 32. Forpurposes of this discussion, the use of the word conductor is generic toboth a bus bar or an electrical wire except that it is to be understoodthat a bus bar is preferable. On the other hand, the right end ofsecondary winding 12 is interconnected with a second common diodesupport heat sink 34 by means of a second conductor 36. The heat sink 30supports an A phase diode 38 which is connected to a common conductor 40associated with one end of the winding of an interphase transformerassembly 44. A second diode 46 is supported in the diode bus assembly 34and is interconnected with a second common conductor bus 50 associatedwith the other end of the winding of the interphase transformer 44.

In a similar fashion, 8" phase secondary winding 14 is connected to asecond pair of diode support heat sinks 54, 56 by means of conductors58, 60 respectively and a pair of diodes 62, 64 are supported on therespective heat sinks 54, 56. The diodes 62, 64 are also connected tothe common conductors 40, 50 respectively. The third phase secondarywinding 16 is connected with a third pair of common heat sink supportassemblies 66, 68 by means of conductors 70, 72, the third pair ofdiodes 74, 76 being supported on the heat sinks 66, 68 respectively.Again, the diodes 74, 76 are connected to the common conductors 40, 50respectively.

Referring particularly to the schematic of the interphase transformer44, it is seen that the transformer includes an interphase winding 80which is connected at one end to one common conductor 40 and at theother end to the other common conductor 50. The conductor 80 is passedthrough the center portion of a magnetic core 82 and thence to theconnection at the common conductor 50. As will be seen from adescription of FIGS. 2 to 8, the conductor 80 comprises a squareconductor, preferably aluminum, with a center hole for supplying coolingfluid thereto, the conductor being bent to pass from the commonconductor 40, through the core 82, to a center tap 86, around theoutside of the core, and back to the other common conductor 50. The core82 may be of the type commonly used in interphase transformers and issupported in a manner to be seen from a further description of FIGS. 2to 8.

The circuit of FIG. 1 illustrates a single set of rectifying diodes in asingle interphase transformer. However, when it is desired to parallel asecond set of diodes in a second interphase transformer, the diodes aremounted in a second set of apertures 88 and includes the exactconfiguration of the diodes 38, 62, 74 and 46, 64, 76. Also, there is asecond interphase transformer with a second set of common conductors 40and 50 connected to the diodes. The center tap 86 of the interphasetransformer 44 is connected with the center tap of the second interphasetransformer to provide a common connection thereto and also a commonconnection to a negative output terminal 90, the terminals 28 and 90forming the output terminals for the load being supplied. Also a furtherset of diode-supporting apertures 94 is provided to provide a third setof parallel diodes and a fourth set of apertures 96 are provided for afourth set of rectifying diodes.

Referring now to FIGS 2 and 3, there is illustrated a typical rectifyingsystem incorporating the features of the present invention.Specifically, the commercial source of power is connected to a pluralityof transformers I00, 102, 104 which form a three-phase input system forthe rectifier. The transformers are supported by means of a supportchannel assembly 106, the details of which are not critical to thepresent invention. As was stated above in connection with FIG. 1, thesecondary windings of the transformers 100, 102, 104 are center tapped,the center tap being in the form of a common bus bar 108, whichcorresponds to the conductor 26 of FIG. I, the common bus bar 108 beingconnected to an output bus 110 which forms the positive terminal for theload circuit.

As was stated above, the ends of the secondary winding areinterconnected with the plurality of diode-mounting heat sink assemblies30, 34, 54, 56, 66 and 68, the right side of the diode heat sinkassemblies illustrated in FIG. 3 and the left side being directly behindthe assemblies illustrated in FIG. 3. The conductors forming theconnections between the ends of the transformer and the diode heat sinkassemblies are formed by bus bars 112, 114, 116, the bus 112 beinginterconnected, by welding, with the diode heat sink assembly 34, thebus 114 being welded to the heat sink assembly 56 and the bus 116 beingwelded to the heat sink assembly 68. As is common in the art, theportions of the bus adjacent but not connected to the remaining diodeheat sink support assemblies are provided with a sufiicient space toavoid corona and short circuiting or are provided with insulatingelements interposed therebetween.

Referring particularly to the details of the heat sink assemblies 34,56, 68, the heat sinks are formed from an extruded aluminum channelhaving a generally flat web section 120 and a pair of fluid-conductingchannels 122, 124 integrally extruded therewith. The central portion ofthe channels 122, 124 are hollow and provided with input and outputfittings 128, 130 which are connected to a cooling fluid supply system(not shown) controlled either by a temperature-sensing or acondensate-sensing system. The condensate is sensed by means of a sensorassembly 136, the assembly controlling a solenoid which controls theflow of cooling fluid to the connections 128, 130. For further detailsof the condensatesensing system, reference is made to copendingapplication of Messrs. Minbiole and Mapham, Ser. No. 88,342, filed Nov.10, 1970 for Condensate-Sensing System, the disclosure of which isincorporated herein by reference. The incoming channel 122 isinterconnected with the outgoing channel 124 by means of a connectingconduit 138, all of the conduits being formed of suitable Nylon or othersynthetic materials.

lnthe illustrated embodiment, two sets of parallel diodes areillustrated as being supported by the diode support assemblies 34, 56,68, the reference numerals of FIG. 1 being applied to the correspondingelements for the first set of diodes 46, 64, 76 and the second set ofdiodes are illustrated at 140, 142, 144. Thus, current flows from thesecondary of the upper transformer 100, through the conductor 112, tothe diode bus assembly 34 through the diodes 46, 140. Similarly, currentflows from the secondary of transformer 102, through the conductor 114,through the diode support assembly 56 to the diodes 64, 142 and, fromthe third transformer 104, through the conductor 116 to the third diodes76, 144 through the third diode support assembly 68. Obviously, thedescription of the details of the diode support heat sink 34 alsoapplies to the details of the diode support heat sink 56 and 68. Theentire rectifier assembly is supported by a plurality of channels 150,152, 154, 156, 158 and 160, as is common in the art.

In the front view of the rectifier assembly, illustrated in FIG 2, theinterconnections between the diodes '46, 64, 76, I40, 142 144 areillustrated wherein the diode includes a connecting conductor 164connected to the common conductor 50 welded to the winding 80 of theinterphase transformer. Similarly, a pigtail 166 is provided with thediode 74 to be connected to the common conductor 40 by means of a boltconnection. Thus, current flows from the diodes 76, 74, and 144, in FIG.2, to the respective windings 80 and a winding 170 of a parallelinterphase transformer assembly 172. As will be seen from a furtherdescription of FIGS. 4 to 8, the windings 80 and 170 are center tappedby means of a common bus, this bus being best illustrated in FIGS. 5 and6. The Bus is disposed generally vertically and appears at the top ofFIG. 2 at 176. The ends of the bus bar 176 are bolted to a standardshunt resistor 180 and then to an output bus assembly 184 by means of aplurality of bolts.

The standard shunt 180 provides a voltage signal for thecurrent-controlling circuits normally utilized in a rectifier system ofthis type, the circuits being illustrated in copending applications ofJames H. Galloway, Ser. No. 5,069, filed .Ian. 22, 1970, for PeakCurrent Limiting System and a copending application of James H.Galloway, Ser. No. 88,340, filed Nov. 10, 1970, for Isolation andTransforming Circuit, the disclosures of which are incorporated hereinby reference.

Obviously, the rectifier of the present invention is provided with thecontrol circuits which are housed either in a panel mounted on the doorof the rectifier assembly or are mounted in an area, designated byreference numeral 186, above the rectifier panel. Certain other sensingsignals are provided, as for example by current transformers 188, 190,and 194, these latter signals sensing the current flowing in theincoming line before it is fed to the main transformer.

The current flowing in the primary winding of the main transformers 100,102 and 104 are controlled by a plurality of controlled rectifierdevices 198, 200 etc., which are connected, in any one phase, inparallel, back-to-back relation by means of a pair of pigtail conductors202, 204 normally supplied with control devices of this type. Thecontrolled rectifiers 198, 200 are mounted on T-shaped heat sinkassemblies 206, 208 respectively which are, in turn, fastened to a mainheat sink assembly 210 by means of a suitable heat-conducting, butelectrically insulating, epoxy. The heat sink assembly 210 is generallyof the same configuration as was described in conjunction with the heatsink assemblies 34, 56 and 68 with the exception that the semiconductordevices are supported by the epoxy. As was the case with heat sinkassemblies 34, 56 and 68, suitable input connections 212 are providedfor supplying cooling fluid thereto, the output being provided atconnection 214. A connection between the tubular extruded apertureswithin the heat sink assembly 210 is provided by means of tubing 218.

The control rectifiers, for example 198 and 200 etc., are fired by acontrol, firing package housed in the area 186, the low voltage outputsignal from the firing package being supplied a plurality of pulsetransformers 220, 224, 226 and 228. It will be noted that the pulsetransformers 220 to 228 are positioned proximate all the controlledrectifiers 198, 200 to be fired thereby permitting a low voltage to beimpressed on the conductors between the firing package in the area 186and the pulse transformers 220 to 228. It will be noted that two pairsof controlled rectifiers are supported behind the circuit boards 230,232 and the circuit boards supplying the firing pulse for controlledrectifiers 198 and 200 has been removed for clarity. The details of thecontrolled rectifier system, with the heat sink and T-bar supportassemblies, are best illustrated and described in copending applicationof Lynn Zellmer, Ser. No. 88,322, filed Nov. 10, 1970, for MountingBracket for semiconductor Rectifiers to Heat Sinks, the disclosure whichis incorporated herein by reference.

Referring now to FIGS. 4, 5 and 6, there are illustrated the specificdetails of the interphase transformer assembly and support therefor. InFIG. 4 there is illustrated a transformer including a core element 240having a cross section such as that illustrated in FIG. 7. The centralportion of the core is provided with a rectangular window adapted toreceive the interphase winding having a portion 242 which is connectedto a lower common conductor 244. The lower common conductor is providedwith a plurality of three apertures 246 for connection to the ends of aplurality of diode pigtails 248, 250 and 252.

The portion 242 of the conductor is welded along its edge thereof to thecommon conductor 244 and the conductor is provided with a right-anglebend to pass through the central portion of the core 240 at 250. Theconductor is then given another right-angle bend such that a portion 252is provided which is parallel to the portion 242 but spaced therefrom.The conductor again turns at a right angle to provide a central or amidpoint portion 254 to which a plurality of bus-bar conductors, in thiscase two conductors 258, 260 are attached. In the illustration of FIG.4, a second pair of conductors 262, 264 are provided, these conductorsbeing welded to the inside of conductor 260 to provide additionalcross-sectional area for the combined current of the upper and lowerinterphase transformers, as will best be seen from a detaileddescription of FIGS. 5 and 6.

The conductor 170 then is given a right-angle bend parallel with aportion 258. The last portion 260 of the conductor is welded to a secondcommon conductor 262, the second portion 262 being parallel to butspaced from the common conductor 244.

The core 240 is squeezingly held between a pair of metallic channels266, 268, the channels being held together solely by a plurality of boltassemblies, including bolts 70, 272. This core support assembly for thecore is best seen in FIGS. and 6 It is to be noted that FIG. 5 does notinclude all of the center-tap conductors described in conjunction withFIG. 4 but rather these conductors have been broken away. The channelelements 266, 268 support the core 240 and a second core 276 issupported immediately below the core 240 in vertical alignmenttherewith. The first core 240 is supported between the bolts 270, 272and a second pair of bolts 278, 280. The second core 276 is supportedbetween the bolts 278, 280 and a third pair of bolts 282, 284. Thus, thecores 240, 276 are supported between the two channels 266, 268, the onlymembers engaging the cores, and the channels are held together by theplurality of bolts. The lower winding, which may correspond to thewinding 80 of FIG. 1, is formed and supported in a manner identical tothat described in conjunction with the description of the winding 170.It will be noted that the common conductors 262, 244 and 40, 50 do notlie in the same horizontal plane but rather are offset, one from theother, due to the vertical overlapping of the conductors 242, 260.

In looking at FIG. 7, it will be noted that the central portion of theconductor 170 is formed with a hollow aperture throughout the conductorto permit cooling fluid to be fed thereto from the same cooling sourcedescribed above for cooling the entire rectifier and particularly thediode support heat sinks. The connections to the conductors 170 and 80may be made in any suitable manner, this arrangement permitting thecooling of the central portion of the core 240.

The core 240 is fabricated by winding a strip of ferromagnetic materialand the core is cut, at 290, to permit the positioning of the conductorportions 250, 258 in a central aperture 292. It will be noted that theconductors 80 and 170 are preformed and merely assembled with the core240. The core 240 is then reassembled and a suitable strap is placedaround the core to hold the core in its assembled state. The coreassembly includes a pair of gaskets 296, 298 which are utilized tofurther support the core within the confines of the channels 266, 268 toprevent damage to the core when it is being squeezed and also topreclude electrical contact between the core assembly and the brackets266, 268.

Referring back to FIGS. 3 and 6, it is seen that the conductors 258,260, 262 and 264 form the center tap and bus conductor 176 described inconjunction with FIG. 2 and appearing at the upper left-hand portion ofFIG. 3. It is to be noted that each time an additional core, for examplecore 240, is added to core 276, an additional pair of vertical buses,for ex ample 262, 264, are added to provide sufficient cross-sectionalarea to accommodate the additional current being carried in the bus 176due to the added transformer.

From the description of FIGS. 4, 5 and 6, it is readily apparent that asmany interphase transformers may be added as are needed for the numberof diodes being paralleled, the addition of the cores and windings beingmade with ease and inexpensively. The additional windings are theninterconnected with additional diodes on the diode support assemblies34, 56, 68, 30, 54, 66 by means of the common conductors welded to thecoil of the added interphase transformer.

Referring now to FIG. 8, there is illustrated a composite figuredepicting a single-core interphase transfonner or a double-coreinterphase'transformer in the case of the lower portion of the figure.For example, the upper core 300 may be rated for l2 volts DC and theidentical core may be utilized in the double configuration shown toprovide 24 volt interphase transformer. Also, if desired, the number ofwindings or laminations on the core 300 may be varied to providevariation in voltages which may be utilized. Thus, for two sizes of coreelements, four voltages may be provided as, for example 9, l2, l8 and 24volts.

While it will be apparent that the preferred embodiments of theinvention disclosed are well calculated to fulfill the objects abovestated, it will be appreciated that the invention is susceptible tomodification, variation and change without departing from the properscope or fair meaning of the subjoined claims.

What is claimed is:

I. In an electrical rectifier assembly which includes at least one diodein each phase of the secondary circuit of a main transformer, aninterphase transformer assembly which comprises:

a core element provided with a window therethrough;

a pair of channel support members disposed on opposite sides of saidcore element, and including means for squeezing said core elementtherebetween;

an interphase winding disposed through said window of said core element;and

means for commonly connecting the at least onediode of each phase tosaid interphase winding.

2. The interphase transformer assembly, as set forth in claim 1, whereinsaid window in said core element is rectangularly shaped.

3. The interphase transformer assembly, as set forth in claim 1, whereinsaid means for squeezing said core elements is a plurality of boltassemblies.

4. The interphase transformer assembly, as set forth in claim I, whereinsaid interphase winding is formed with a hollow aperture therethrough.

5. The interphase transformer assembly, as set forth in claim 4, whereinheat is transferred from the core element by communicating a coolingfluid through said hollow aperture of said interphase winding.

6. The interphase transformer assembly, as set forth in claim I, whereinsaid interphase winding is formed to define a rectangular shape havingadjacent sides in relationship, with said core being disposed at the midpoint portion thereof.

7. The interphase transformer assembly, as set forth in claim 6, whereina common conductor is connected to one side of said interphase windings,said common conductor connecting at least one diode in each phase of thesecondary circuit.

8. In an electrical rectifier assembly which includes at least one diodein each phase of the secondary circuit of a main transformer, aninterphase transformer assembly which comprises:

a core element provided with a window therethrough;

a hollow interphase winding disposed through said window of said coreelement;

means for commonly connecting the at least one diode of each phase tosaid interphase winding; and

means for cooling said core element from said winding by passing acooling fluid through said hollow interphase winding.

9. The interphase transformer assembly, as set forth in claim 8, furtherincluding a pair of channel support members disposed on opposite sidesof said core element, and including means for squeezing said coreelement therebetween.

10. The interphase transformer assembly, as set forth in claim 9,wherein said means for squeezing said core elements is a plurality ofbolt assemblies.

II. The interphase transformer assembly, as set forth in claim 8,wherein said interphase winding is formed to define a rectangular shapehaving adjacent sides in 90 relationship, with said core being disposedat the mid point portion thereof.

12. The interphase transformer assembly, as set forth in claim 11,wherein a common conductor is connected to one side of said interphasewindings, said common conductor connecting at least one diode in eachphase of the secondary circuit.

13. The interphase transformer assembly as set forth in claim 1, furtherincluding a second transformer assembly having a core element providedwith a window therethrough. a second interphase winding disposed throughsaid window of said core element, a second set of at least one diode ineach phase of the secondary circuit of the main transformer, means forconnecting said first and second set of diodes in parallel with saidmain transformer, means for commonly connecting the second set of diodesof each phase to said second interphase winding, the core element ofsaid first interphase transformer and the core element of said secondinterphase transformer being commonly supported by said channel supportmembers.

14. The improvement of claim 13, wherein said cores are verticallysupported, one above the other.

15. The improvement of claim 14, wherein said first and secondinterphase windings include a center tap for each winding, and means forcommonly connecting said first and second center taps.

16. The interphase transformer assembly as set forth in claim 8, furtherincluding a second transformer assembly having a core element providedwith a window therethrough, a second interphase winding disposed throughsaid window of said core element, a second set of at least one diode ineach phase of the secondary circuit of the main transformer, means forconnecting said first and second set of diodes in parallel with saidmain transformer, means for commonly connecting the second set of diodesof each phase to said second interphase winding, the core element ofsaid first interphase transformer and the core element of said secondinterphase transfonner being commonly supported by said channel supportmembers.

17. The improvement of claim '16, wherein said cores are verticallysupported, one above the other.

18. The improvement of claim 17, wherein said first and -secondinterphase windings include a center tap for each winding, and means forcommonly connecting said first and second center taps.

t i 1 F

1. In an electrical rectifier assembly which includes at least one diodein each phase of the secondary circuit of a main transformer, aninterphase transformer assembly which comprises: a core element providedwith a window therethrough; a pair of channel support members disposedon opposite sides of said core element, and including means forsqueezing said core element therebetween; an interphase winding disposedthrough said window of said core element; and means for commonlyconnecting the at least one diode of each phase to said interphasewinding.
 2. The interphase transformer assembly, as set forth in claim1, wherein said window in said core element is rectangularly shaped. 3.The interphase transformer assembly, as set forth in claim 1, whereinsaid means for squeezing said core elements is a plurality of boltassemblies.
 4. The interphase transformer assembly, as set forth inclaim 1, wherein said interphase winding is formed with a hollowaperture therethrough.
 5. The interphase transformer assembly, as setforth in claim 4, wherein heat is transferred from the core element bycommunicating a cooling fluid through said hollow aperture of saidinterphase winding.
 6. The interphase transformer assembly, as set forthin claim 1, wherein said interphase winding is formed to define arectangular shape having adjacent sides in 90* relationship, with saidcore being disposed at the mid point portion thereof.
 7. The interphasetransformer assembly, as set forth in claim 6, wherein a commonconductor is connected to one side of said interphase windings, saidcommon conductor connecting at least one diode in each phase of thesecondary circuit.
 8. In an electrical rectifier assembly which includesat least one diode in each phase of the secondary circuit of a maintransformer, an interphase transformer assembly which comprises: a coreelement provided with a window therethrough; a hollow interphase windingdisposed through said window of said core element; means for commonlyconnecting the at least one diode of each phase to said interphasewinding; and means for cooling said core element from said winding bypassing a cooling fluid through said hollow interphase winding.
 9. Theinterphase transformer assembly, as set forth in claim 8, furtherincluding a pair of channel support members disposed on opposite sidesof said core element, and including means for squeezing said coreelement therebetween.
 10. The interphase transformer assembly, as setforth in claim 9, wherein said means for squeezing said core elements isa plurality of bolt assemblies.
 11. The interphase transformer assembly,as set forth in claim 8, wherein said interphase winding is formed todefine a rectangular shape having adjacent sides in 90* relationship,with said core being disposed at the mid point portion thereof.
 12. Theinterphase transformer assembly, as set forth in claim 11, wherein acommon conductor is connected to one side of said interphase windings,said common conductor connecting at least one diode in each phase of thesecondary circuit.
 13. The interphase transformer assembly as set forthin claim 1, further including a second transformer assembly having acore element provided with a window therethrough, a second interphasewinding disposed through said window of said core element, a second setof at least one diode in each phase of the secondary circuit of the maintransformer, means for connecting said first and second set of diodes inparallel with said main transformer, means for commonly connecting thesecond set of diodes of each phase to said second interphase winding,the core element of said first interphase transformer and the coreelement of said second interphase transformer being commonly supportedby said channel support members.
 14. The improvement of claim 13,wherein said cores are vertically supported, one above the other. 15.The improvement of claim 14, wherein said first and second interphasewindings include a center tap for each winding, and means for commonlyconnecting said first and second center taps.
 16. The interphasetransformer assembly as set forth in claim 8, further including a secondtransformer assembly having a core element provided with a windowtherethrough, a second interphase winding disposed through said windowof said core element, a second set of at least one diode in each phaseof the secondary circuit of the main transformer, means for connectingsaid first and second set of diodes in parallel with said maintransformer, means for commonly connecting the secoNd set of diodes ofeach phase to said second interphase winding, the core element of saidfirst interphase transformer and the core element of said secondinterphase transformer being commonly supported by said channel supportmembers.
 17. The improvement of claim 16, wherein said cores arevertically supported, one above the other.
 18. The improvement of claim17, wherein said first and second interphase windings include a centertap for each winding, and means for commonly connecting said first andsecond center taps.